An international team of astronomers has made a measurement of a distant neutron star that is one million times more precise than the previous world’s best.
The researchers were able to use the interstellar medium, the ’empty’ space between stars and galaxies that is made up of sparsely spread charged particles, as a giant lens to magnify and look closely at the radio wave emission from a small rotating neutron star.
This technique yielded the highest resolution measurement ever achieved, equivalent to being able to see the double-helix structure of our genes from the Moon!
“Compared to other objects in space, neutron stars are tiny — only tens of kilometres in diameter — so we need extremely high resolution to observe them and understand their physics,” Dr Jean-Pierre Macquart from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR) in Perth said.
Neutron stars, or pulsars, have intense magnetic fields and fast rotation, with some turning as many as 1,000 times per second, redOrbit reported. They are also able to emit strong beams of light across the whole electromagnetic spectrum. However, most of the specific physics of the stars’ activity has yet to be discovered.
“More than 45 years since astronomers discovered pulsars, we still don’t understand the mechanism by which they emit radio waves pulses,” Macquart said.
Pulsars are very far away from Earth, and their small size makes it harder to find them.
“The best we could previously do was pointing a large number of radio telescopes across the world at the same pulsar, using the distance between the telescopes on Earth to get good resolution,” Macquart stated.
The team was led by Professor Ue-Li Pen of the Canadian Institute of Theoretical Astrophysics. Analysts were able to show that their “interstellar lens” could get an angular resolution of 50 picoarcseconds, which provided a million times more detail than the previous record, which had a resolution of 50 microarcseconds, e! Science News reported.
The researchers tested the method on Pulsar B0834+06 and discovered that the neutron star’s emission was smaller than previously believed and might be closer to the surface of the star. The finding could be important in learning about the radio wave emission’s origin.
“What’s more, this new technique also opens up the possibilities for precise distance measurements to pulsars that orbit a companion star and ‘image’ their extremely small orbits- which is ultimately a new and highly sensitive test of Einstein’s theory of General Relativity,” Pen said.